For anyone else who has the same need to remove a pending update, there's one detail I omitted. That path:
C:\Documents and Settings\Administrator\Local Settings\Temp\CUtilNETOPERA
containing the temporary copy of all the browser files and downloaded update file, will have a different name on your machine. The "CUtilNETOPERA" part is constructed from the path of the Opera install, which on my machine is: C:\Util\NET\OPERA
On your machine it will be a concatenation of your Opera install path.
Also, obviously the 'Administrator' part will be your username.